It is not always to just "ground their power" to neutralize it. Oh were it so. That is far...far.. too simplistic. At a point when they are not using dumb force; things can get dicey and you need to be capable of much more. In a face off with other people with better understanding of power you will be played and manipulated rather than them let you have a stand off of power to power, Hell even a good soft wrestler (yes they exist) will pick that apart. At that time, the ability to make change far surpasses the one point connected model.
There are reasons that Tohei swayed sometime under force and moved differently than Ueshiba. His model was a starting point and that's about it. I know some people here are big fans, but I never was. It is one level. A beginning step. I have looked for certain things in him and never seen them. Well, I haven't seen them in anyone in Aikido...yet. And In my opinion, In comparison I think Shioda was more developed. Moving from the one point while compelling and potent....can be stilted and can be had. In a fight... it can see you undone.
The one point, expressed and evident at any point on the body can still be manipulated. In fact beyond a certain point, it's all about manipulation inside...and that is where it all gets interesting. At that juncture the one point is no longer even in the discussion, as it is a given. To put it another way, there is so much Tohei did not discuss and was not evident in his movement either so I do not believe it was for lack of desire to discuss it.
With others actively teaching and for "demonstrations of Ki"...I will reserve my opinions for them and them alone, Yup, it is that protective. I continue to meet Shihan and other prominent people in the arts. Since, I actually
wish to help, with no agenda, I would rather honor someone for stepping up and help improve their game in private.